PDF(Pubmed)
Abstract：
BACKGROUND: Lung ischemia-reperfusion (I/R) injury is a serious clinical problem without effective treatment. Enhancing branched-chain amino acids (BCAA) metabolism can protect against cardiac I/R injury, which may be related to bioactive molecules generated by BCAA metabolites. L-β-aminoisobutyric acid (L-BAIBA), a metabolite of BCAA, has multi-organ protective effects, but whether it protects against lung I/R injury is unclear.
METHODS: To assess the protective effect of L-BAIBA against lung I/R injury, an animal model was generated by clamping the hilum of the left lung, followed by releasing the clamp in C57BL/6 mice. Mice with lung I/R injury were pre-treated or post-treated with L-BAIBA (150 mg/kg/day), given by gavage or intraperitoneal injection. Lung injury was assessed by measuring lung edema and analyzing blood gases. Inflammation was assessed by measuring proinflammatory cytokines in bronchoalveolar lavage fluid (BALF), and neutrophil infiltration of the lung was measured by myeloperoxidase activity. Molecular biological methods, including western blot and immunofluorescence, were used to detect potential signaling mechanisms in A549 and BEAS-2B cells.
RESULTS: We found that L-BAIBA can protect the lung from I/R injury by inhibiting ferroptosis, which depends on the up-regulation of the expressions of GPX4 and SLC7A11 in C57BL/6 mice. Additionally, we demonstrated that the Nrf-2 signaling pathway is key to the inhibitory effect of L-BAIBA on ferroptosis in A549 and BEAS-2B cells. L-BAIBA can induce the nuclear translocation of Nrf-2. Interfering with the expression of Nrf-2 eliminated the protective effect of L-BAIBA on ferroptosis. A screening of potential signaling pathways revealed that L-BAIBA can increase the phosphorylation of AMPK, and compound C can block the Nrf-2 nuclear translocation induced by L-BAIBA. The presence of compound C also blocked the protective effects of L-BAIBA on lung I/R injury in C57BL/6 mice.
CONCLUSIONS: Our study showed that L-BAIBA protects against lung I/R injury via the AMPK/Nrf-2 signaling pathway, which could be a therapeutic target.
L-BAIBA upregulates the expression of GPX4 and SLC7A11 by activating the AMPK/Nrf-2/GPX4/SLC7A11 signaling pathway, thereby protecting against I/R-induced increase in ROS and ferroptosis in the lung.
METHODS: To assess the protective effect of L-BAIBA against lung I/R injury, an animal model was generated by clamping the hilum of the left lung, followed by releasing the clamp in C57BL/6 mice. Mice with lung I/R injury were pre-treated or post-treated with L-BAIBA (150 mg/kg/day), given by gavage or intraperitoneal injection. Lung injury was assessed by measuring lung edema and analyzing blood gases. Inflammation was assessed by measuring proinflammatory cytokines in bronchoalveolar lavage fluid (BALF), and neutrophil infiltration of the lung was measured by myeloperoxidase activity. Molecular biological methods, including western blot and immunofluorescence, were used to detect potential signaling mechanisms in A549 and BEAS-2B cells.
RESULTS: We found that L-BAIBA can protect the lung from I/R injury by inhibiting ferroptosis, which depends on the up-regulation of the expressions of GPX4 and SLC7A11 in C57BL/6 mice. Additionally, we demonstrated that the Nrf-2 signaling pathway is key to the inhibitory effect of L-BAIBA on ferroptosis in A549 and BEAS-2B cells. L-BAIBA can induce the nuclear translocation of Nrf-2. Interfering with the expression of Nrf-2 eliminated the protective effect of L-BAIBA on ferroptosis. A screening of potential signaling pathways revealed that L-BAIBA can increase the phosphorylation of AMPK, and compound C can block the Nrf-2 nuclear translocation induced by L-BAIBA. The presence of compound C also blocked the protective effects of L-BAIBA on lung I/R injury in C57BL/6 mice.
CONCLUSIONS: Our study showed that L-BAIBA protects against lung I/R injury via the AMPK/Nrf-2 signaling pathway, which could be a therapeutic target.
L-BAIBA upregulates the expression of GPX4 and SLC7A11 by activating the AMPK/Nrf-2/GPX4/SLC7A11 signaling pathway, thereby protecting against I/R-induced increase in ROS and ferroptosis in the lung.
摘要：
背景：肺缺血再灌注（I/R）损伤是一个严重的临床问题，没有有效的治疗方法。增强支链氨基酸（BCAA）代谢可以防止心脏I/R损伤，这可能与BCAA代谢物产生的生物活性分子有关。L-β-氨基异丁酸(L-BAIBA),BCAA的代谢产物,具有多器官保护作用，但它是否能预防肺I/R损伤尚不清楚。
方法：为了评估L-BAIBA对肺I/R损伤的保护作用，通过夹住左肺门产生动物模型，然后在C57BL/6小鼠中释放夹钳。将具有肺I/R损伤的小鼠用L-BAIBA(150mg/kg/天)预处理或后处理,通过管饲法或腹膜内注射给予。通过测量肺水肿和分析血气来评估肺损伤。通过测量支气管肺泡灌洗液（BALF）中的促炎细胞因子来评估炎症，通过髓过氧化物酶活性测量肺的中性粒细胞浸润。分子生物学方法,包括蛋白质印迹和免疫荧光，用于检测A549和BEAS-2B细胞中的潜在信号传导机制。
结果：我们发现L-BAIBA可以通过抑制铁凋亡来保护肺免受I/R损伤，这取决于C57BL/6小鼠中GPX4和SLC7A11表达的上调。此外,我们证明Nrf-2信号通路是L-BAIBA抑制A549和BEAS-2B细胞铁凋亡的关键。L-BAIBA可诱导Nrf-2的核转位。干扰Nrf-2的表达消除了L-BAIBA对铁凋亡的保护作用。筛选潜在的信号通路显示L-BAIBA可以增加AMPK的磷酸化,化合物C可以阻断L-BAIBA诱导的Nrf-2核易位。化合物C的存在还阻断了L-BAIBA对C57BL/6小鼠肺I/R损伤的保护作用。
结论：我们的研究表明，L-BAIBA通过AMPK/Nrf-2信号通路保护肺I/R损伤，这可能是一个治疗目标。
L-BAIBA通过激活AMPK/Nrf-2/GPX4/SLC7A11信号通路上调GPX4和SLC7A11的表达,从而防止I/R诱导的肺中ROS和铁凋亡的增加。
方法：为了评估L-BAIBA对肺I/R损伤的保护作用，通过夹住左肺门产生动物模型，然后在C57BL/6小鼠中释放夹钳。将具有肺I/R损伤的小鼠用L-BAIBA(150mg/kg/天)预处理或后处理,通过管饲法或腹膜内注射给予。通过测量肺水肿和分析血气来评估肺损伤。通过测量支气管肺泡灌洗液（BALF）中的促炎细胞因子来评估炎症，通过髓过氧化物酶活性测量肺的中性粒细胞浸润。分子生物学方法,包括蛋白质印迹和免疫荧光，用于检测A549和BEAS-2B细胞中的潜在信号传导机制。
结果：我们发现L-BAIBA可以通过抑制铁凋亡来保护肺免受I/R损伤，这取决于C57BL/6小鼠中GPX4和SLC7A11表达的上调。此外,我们证明Nrf-2信号通路是L-BAIBA抑制A549和BEAS-2B细胞铁凋亡的关键。L-BAIBA可诱导Nrf-2的核转位。干扰Nrf-2的表达消除了L-BAIBA对铁凋亡的保护作用。筛选潜在的信号通路显示L-BAIBA可以增加AMPK的磷酸化,化合物C可以阻断L-BAIBA诱导的Nrf-2核易位。化合物C的存在还阻断了L-BAIBA对C57BL/6小鼠肺I/R损伤的保护作用。
结论：我们的研究表明，L-BAIBA通过AMPK/Nrf-2信号通路保护肺I/R损伤，这可能是一个治疗目标。
L-BAIBA通过激活AMPK/Nrf-2/GPX4/SLC7A11信号通路上调GPX4和SLC7A11的表达,从而防止I/R诱导的肺中ROS和铁凋亡的增加。
